WHAT IT'S ABOUT The day begins at 11 a.m., London time. The CIA is hunting a "high value target" -- Jack Bauer (Kiefer Sutherland), on the run four years, or ever since Chloe O'Brian (Mary Lynn Rajskub) "surveilled" him from a drone over New York City. Afterwards, Jack had seemed to vanish forever ("24" ended May 24, 2010, after eight seasons). Bauer was a wanted man - by the Russians and the Americans - at the end of the so-called "8th day," and he still is.

But why is Jack in London? CIA station chief Steve Navarro (Benjamin Bratt) wants to grab Jack before he can do any damage -- the U.S. president, James Heller, formerly the Secretary of Defense (William Devane) is in the city, along with his daughter, Audrey Raines (Kim Raver) and her husband, Heller's chief of staff, Mark Boudreau (Tate Donovan). A CIA agent, Kate Morgan (Yvonne Strahovski), is understandably wary of Jack. But one of her rivals, Erik Ritter (Gbenga Akinnagbe), is wary of her.

This 12-part "special event" is expected to be the bookend to a classic series. Sutherland has said no sequels will be produced. So this is, truly, the end.

MY SAY Your first sighting of Jack Bauer in the first episode is through the lens of a surveillance camera mounted on a crablike gizmo that has skittered across the floor of a grimy flophouse. There, in a split second, is the half-lit image of someone crouching over the body of a pursuer he has just immobilized. Bauer then glances -- no, GLARES over to the camera to stare straight back at . . . YOU.

A nicely economical shot, this tells you almost everything you need to know about Jack since last seen, most notably this: He's still got plenty of unfinished business in the alt-universe of "24," which seemed to end for good almost exactly four years ago.

Four years in fact haven't really seemed to change Jack all that much. He's still all coiled rage and vengeance -- a one-man wrecking crew, a weaponized piece of human flesh and bone.

What's changed, in fact, is us. Since that last season in New York, and even during some of the faltering ones that preceded, TV (and culture) went off in a different direction. The new TV heroes were of the "anti" variety -- Don Draper, or Walter White -- who struggled with their blighted souls as opposed to blighted superpowers or narco-terrorists. Jack Bauer had become antiquated. Watching him crawl out of the gloom Monday night, it's hard to shake the sense that he still is obsolete.

But that doesn't mean it's not good to have him back. It is good -- very good -- made even better because we know we won't be groaning our way through hours 22 and 23, as the last crazy plot twists rend logic, plausibility and patience (ours). Jack does have unfinished business but it's nice to know he only has twelve hours to get it done.

Besides Jack, "Live Another Day" rolls out the welcome mat in all sorts of other ways. For one, the ever-indispensable Chloe returns as a sartorially tricked-out cyber-punk, all dressed in black and -- like Jack -- a patriot without country. Devane's Heller and Raver's Raines, who were characters from the late golden age of "24" ("Day 6"), get a chance to wrap their own incomplete stories as well. Meanwhile, every classic "24" trick and trope is here to remind us why we got so excited about this show in the first place.

And for the requisite contemporary touches, "Live Another Day" is a banquet of current affairs issues -- or at least a salad bar at TGIF's. Drones, Afghanistan and leaked government documents -- cue to Edward Snowden -- are all key plot points. But at least in the opening hours, they all feel more like slick gimmicks used to bring Jack and his latest "worst day" up to date, as opposed to a half-baked attempt at political commentary.